Subject: Would a bouyant sphere released from ocean depths be heated by frictio

Jules Verne wrote a story about a scientist lowered to the bottom of a deep 
ocean trench in a completely self contained steel sphere.  This sphere was 
to be released by a "clockwork mechanism" (brave scientist!). His 
companions wait anxiously on the surface fearing the worst when a suddenly 
an object hurtles out of the sea rises into the air and drops back into the 
ocean.. His companions row over to release the scientist and find him 
overcome by the heat of his ascent and the rubber! seals of his craft 
melted.  I have long wondered if the cooling effect of sea water wouldn't 
have countered such heat as a fast rising body might have generated.  
What's the truth here?  Would the sphere reach a maximum speed.  Would 
diminiashing water pressure make a difference.  Its intrigued me 

Re: Would a bouyant sphere released from ocean depths be heated by frictio